Discount Calculator
Find the sale price and how much you save with one or several stacked percentage discounts, a coupon amount and optional sales tax.
Results are estimates for information only, not financial advice. Check with a professional before making decisions.
- Sale price
- –
- You save
- –
- Total discount
- –
- Price with tax
- –
| Discount | Saving | Price after |
|---|
How it was calculated
How to use the discount calculator
- Enter the Original price of the item.
- Type the Discount (%), for example 25 for “25% off”.
- If a second or third reduction applies (an extra “take another 10% off at the register”, a member discount…), fill in Second discount (%) and Third discount (%). Leave them empty otherwise.
- For a coupon worth a fixed amount, enter the Amount off (coupon) and choose whether to Apply the amount off After the percentages or Before the percentages.
- Optionally, enter the Sales tax (%) to see the price you will pay at the checkout, and choose the Currency.
The Sale price, what You save, the Total discount as a percentage of the original price and the Price with tax update as you type. The Discount by discount table shows the saving and the price after each reduction, and How it was calculated shows the formulas. Use Copy to paste the result elsewhere.
Formula for a single discount
For a price P and a discount d%:
- saving = P × d / 100
- sale price = P × (1 − d / 100)
Example: 25% off $80 saves $20, and the sale price is $60. Each step is rounded to the cent, as a cash register does.
Why 20% + 10% is not 30%
Stacked discounts are successive: the second percentage applies to the price that is already reduced, not to the original price. With 20% then 10% off $80:
- $80 × (1 − 0.20) = $64
- $64 × (1 − 0.10) = $57.60
You save $22.40, that is 28%, not 30%. The combined rate of several discounts is:
total = 1 − (1 − d₁) × (1 − d₂) × (1 − d₃)
Two 50% discounts give 75% off, not a free item. The order of the percentages does not change the result. When several percentages are entered, a message under the fields compares the sum with the real total.
Coupons in dollars: the order matters
A fixed amount off behaves differently. With $10 off and 20% + 10% off $80:
- After the percentages: $57.60 − $10 = $47.60.
- Before the percentages: ($80 − $10) × 0.8 × 0.9 = $50.40.
Taking the dollar amount last is better for the customer. Stores decide which order they use, so check the terms of the promotion.
Frequently asked questions
How do I find the discount percentage from two prices?
Divide the saving by the original price: (80 − 60) / 80 = 25%. You can also try a few values in the Discount (%) field until the sale price matches.
Is sales tax charged before or after the discount?
In Canada, sales tax is normally calculated on the price after the store’s discount. Manufacturer coupons can be treated differently, so the receipt may vary.
Why is my saving a cent different from the store's?
This tool rounds each step to the cent. Some stores round only at the end, or round each item on a multi-item receipt, which can move the total by a cent.
Can I use this for markups or price increases?
Not directly: a discount cannot exceed 100%. For increases, use a percentage calculator.
Does this tool give financial advice?
No. It performs arithmetic on the numbers you enter. The price you pay is the one on your receipt.
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